Bimetallic reactivity. Preparation and properties of bimetallic complexes formed by binucleating ligands bearing 4-and 6-coordinate sites

Four binucleating ligands bearing 4- and 6-coordinate sites employing pheno late bridges have been prepared. Bimetallic copper(II) and nickel(II) compl exes of some of these ligands have been isolated and characterized. Crystal structures of two of the cooper(II) complexes have been determined. A mono metallic manganese(II) complex of one of these ligands was isolated. Upon e xposure to dioxygen, acetonitrile solutions of the complex in the presence of chloride ions lead to the formation of a manganese(IV) complex. The crys tal structure of this complex is reported, and it is shown that the metal i s in the 4-coordinate ligand site and is bound to two chloride ions.